Temporal processing properties of the auditory system in cochlear implant users Description of the Project One of the major challenges in cochlear implants (CIs) is the large variability in CI patients'speech perception performance. Recent studies have shown significant correlations between this variability in speech performance and CI patients'psychophysically measured temporal processing. Besides these behavioral measures, the temporal properties of neural responses to repeated stimuli provide important information about the auditory system's processing of temporal cues in sounds. It is unclear how objectively measured neural responses are related to behavioral measures of temporal processing and speech perception. The goal of this project is to investigate the temporal properties of four types of auditory evoked potentials (AEPs) in CI patients: 1) the electric compound action potential (ECAP), 2) the electric auditory brainstem response (EABR), 3) the electric late auditory evoked potential (ELAEP), and 4) the acoustic LAEP. We will compare neurophysiological and behavioral measures of temporal processing and speech perception abilities in CI users. We hypothesize that the temporal properties of the LAEP are better correlated to behavioral measures than those of the ECAP and the EABR. Theoretically, the results from the proposed study will provide important insights into the large variability in CI patients'speech understanding. Practically, the proposed research will help to identify appropriate electrophysiological measures that can be used to objectively assess CI benefits. This research may lead to future efforts toward improving the temporal representation of sounds in CI users. PUBLIC HEALTH RELEVANCE: This project examines how the auditory system of cochlear implant users processes information of sounds over time using electrophysiological and behavioral methods. It will provide important insights into why some patients receive greater benefits than others from implantation. It will also lead to the identification of the most promising electrophysiological tools that can be used to objectively measure outcomes of implantation or the efficacy of rehabilitation strategies.